Ethereum explained – Casper and Proof-of-Stake

Casper will play an important role in this process, and now is an opportune time to explain what this project is all about.
In the case of Ethereum, the worst-case economic analysis is the only correct way to analyze consensus protocols intended to be suited for public consensus.
For Ethereum, that attack can come from various angles under the current implementation, including colluding nodes under bad behavior.
But there is more to Casper than “just” Ethereum protocol security, as the project is designed to be light client-friendly.
Source: Ethereum DevCon1 2015
Images courtesy of Ethereum